Cheney Boone, the Director of the Bureau of Price Regulation (BPR)[3] is beaten to death with a monkey wrench shortly before a speech he is to deliver at a gathering of the National Industrial Association (NIA), a prominent conglomeration of big business interests.

This attracts the attention of Nero Wolfe, who is facing financial ruin, and with the help of Archie Goodwin he launches a scheme to manipulate the NIA into hiring his services to find the killer.

Wolfe arranges a meeting between the principal witnesses to the case—Boone's widow and niece, acting BPR director Solomon Dexter and researcher Alger Kates, the NIA executive committee, and select members of law-enforcement including Inspector Cramer and Sgt.

The meeting soon degenerates into chaos and bickering, but Wolfe is intrigued by the absence of Phoebe Gunther, Boone's private secretary and the last person to see him alive, and orders Archie to bring her to him for questioning.

Phoebe, a passionate BPR supporter, intended to reveal it once the NIA had been damaged as much as possible by the controversy over Boone's death, but managed to alert the murderer that she was aware of his identity and was killed for her silence.

After a meeting with Boone's widow, where she confirms that Phoebe did indeed possess the cylinders, Wolfe takes the unprecedented step of terminating his contract with the NIA and returning the group's $30,000 fee.

When played, both Wolfe and Cramer are vindicated; the murderer is revealed to be Alger Kates, who was bribed by Don O'Neill to pass on confidential BPR information and was exposed on the cylinder as a traitor.

Having heard the cylinder, Phoebe discovered his guilt but revealed her knowledge to Kates when after pressuring him to return numerous items, possessing sentimental value to Boone's widow, that were stolen from the corpse to fake a theft.

The Silent Speaker contains just this one: For the BPR: For the NIA: For New York law enforcement: The reader is given the opportunity to see how much Wolfe's attitude toward sentiment changes over a brief span of time.

Other members of the cast (in credits order) are Debra Monk (Mrs. Boone), Colin Fox (Fritz Brenner), Bill Smitrovich (Inspector Cramer), Cynthia Watros (Phoebe Gunther), Joe Flaherty (Dr. Vollmer), George Plimpton (Winterhoff), James Tolkan (FBI Agent Richard Wragg), Conrad Dunn (Saul Panzer), Fulvio Cecere (Fred Durkin), David Schurmann (Frank Erskine), Christine Brubaker (Hattie Harding), Bill MacDonald (Breslow), Matthew Edison (Edward Erskine), R.D.

Reid (Sergeant Purley Stebbins), Nicky Guadagni (Mrs. Cramer/Secretary), Richard Waugh (Don O'Neill), Manon von Gerkan (Nina Boone), Julian Richings (Alger Kates), Robert Bockstael (Solomon Dexter), Gary Reineke (Hombert), Steve Cumyn (Skinner) and Doug Lennox (Inspector Ash).